That doesn't make sense, I assume it's a spammer.
Anyway, I put your CSS on my server to see if I could spot the issue, but I doubt I was accurately representing your page. Could you link to a working example?
Since the gap gets bigger as resolution improves it must be controlled by percentage. Probably by the relationship between the parent and child, rather than a set value. If that
padding: 10px; is meant to be defining a constant width gap, then you would likely have to remove the width value of that element for it to work consistently.